diff --git a/visualdl/backend/logic/pybind.cc b/visualdl/backend/logic/pybind.cc
index c977963ee03ae702adf3b984ea154c59079daac0..242c25d3e1a80a7704dcfddbaa62775ad1dbde20 100644
--- a/visualdl/backend/logic/pybind.cc
+++ b/visualdl/backend/logic/pybind.cc
@@ -35,6 +35,7 @@ PYBIND11_MODULE(core, m) {
   py::class_<vs::StorageHelper>(m, "Storage")
       .def("timestamp", &vs::StorageHelper::timestamp)
       .def("dir", &vs::StorageHelper::dir)
+      .def("set_dir", &vs::StorageHelper::SetDir)
       .def("tablets_size", &vs::StorageHelper::tablets_size)
       .def("buffer", &vs::StorageHelper::buffer)
       .def("human_readable_buffer", &vs::StorageHelper::human_readable_buffer)
diff --git a/visualdl/backend/logic/test.py b/visualdl/backend/logic/test.py
deleted file mode 100644
index 3604089892a0b03cdc5289ea683f41fe37ffcb67..0000000000000000000000000000000000000000
--- a/visualdl/backend/logic/test.py
+++ /dev/null
@@ -1,11 +0,0 @@
-import core
-
-im = core.im()
-
-im.add_tablet("tag0", 50)
-
-tablet = im.tablet("tag0")
-tablet.add_scalar_int32(1, 13)
-
-print "buffer", tablet.buffer()
-print "buffer", tablet.human_readable_buffer()
diff --git a/visualdl/backend/test.py b/visualdl/backend/test.py
new file mode 100644
index 0000000000000000000000000000000000000000..f0cd54d65325c04e3d5f8da19019f8f698329a59
--- /dev/null
+++ b/visualdl/backend/test.py
@@ -0,0 +1,46 @@
+import sys
+import unittest
+sys.path.append('../../build')
+import core
+
+im = core.im()
+
+class StorageTester(unittest.TestCase):
+    def setUp(self):
+        self.storage = im.storage()
+
+    def test_size(self):
+        self.assertEqual(self.storage.tablets_size(), 0)
+        im.add_tablet("tag0", 100)
+        self.assertEqual(self.storage.tablets_size(), 1)
+
+        for i in range(1, 11):
+            im.add_tablet("tag%d" % i, 100)
+        self.assertEqual(self.storage.tablets_size(), 11)
+
+    def test_timestamp(self):
+        print self.storage.timestamp()
+
+    def test_dir(self):
+        dir = "./1.txt"
+        self.storage.set_dir(dir)
+        self.assertEqual(dir, self.storage.dir())
+
+    def test_human_readable_buffer(self):
+        print self.storage.human_readable_buffer()
+
+
+class TabletTester(unittest.TestCase):
+    def setUp(self):
+        self.tablet = im.add_tablet("tag101", 20)
+
+    def test_add_scalar(self):
+        self.tablet.add_scalar_float(1, 0.3)
+        self.assertEqual(self.tablet.records_size(), 1)
+
+    def test_human_readable_buffer(self):
+        print self.tablet.human_readable_buffer()
+
+
+if __name__ == '__main__':
+    unittest.main()